Guangdong Dongguan is in the southeast of Henan, Henan is in the north, Guangdong is in the south, and Dongguan is in the south of Henan. Southeast, to be exact.
Dongguan generally refers to the prefecture-level cities and megacities under the jurisdiction of Guangdong Province, and Dongguan, the central city on the east coast of the Pearl River Delta approved by the State Council.